Glass severing method and apparatus



ug- 19, 1952 R. B. RANDELS GLASS SEVERING METHOD AND APPARATUS Filed March 22, 1948 nbentur HEL',

h lll llllllllllllllllllllg Patented Aug. 19, 1952 GLASS SEVERING METHOD AND APPARAfrUS f Robert B. Randels, Corning, N. Y., assignor to Corningv Glass Works, Corning, N. Y., a ecrporaton of New York I ".ApplieatidnMarlch 22, 1948, Serial No. 16,255

The present invention relates to methods of and apparatus for serving compressible bodies of frangible material, such, for example, as ceramics and the like, and is particularly/concerned with 9 Claims. (01.49-48) creasing the compressive force. Whether a tubular article is scored on its inner or outer surface is wholly a matter of choice or convenience, dictated for the most part fby the design of'the the provision of methods and facilities suitable 5 apparatus and/or the bore diameter of the for severing tubular glass bodies. l l article.

It is common practice to sever a tubular glass 'I'he accompanying drawing illustrates simple body by thermal Shock or by abrading a surface forms of structures embodying the invention by thereof and applying a bending force to complete means of which applicants methods may be the severance. severing tubes in the Vforegoing i carried out. fashion may be done rapidly, but the ends' are In the drawing, uneven and usually require subsequent precison Fig. 1 is a front elevation of an apparatus em- 'trimming bodying the invention, by means of which appli- The prime objects of the present invention are 1 cants method may be practiced, with a lower tube-severing methods which effect severance portion broken away and with a piece of tubing not only with rapidity, but also with a' degree of held therein preparatory to its severance. accuracy making a subsequent trimming'op'era- Fig.`2 is a side elevation of the complete aption unnecessary. paratus of Fig. 1. f

Other objects are improved wholly mechanical Fig. 2a is a longitudinal sectional elevation of tube-severing methods. l the tubing and of a part of the apparatus of Stilllfurther objects are simple forms of appa- Figs.Y l and 2, a portion of the tubing being someratus by means of which the foregoing methods what distorted for emphasis. may be readily carried out. l Fig. 3 is a side elevation'of a modified form of The foregoing methods involve introducing inapparatus having -a piece of tubing clamped to a compressible body a localized, radial, com- 20 therein.' pressive force or load over a circumferential area Fig. 4 is a View of a fragment of Fig.y 3 as seen to create a circumferential band of maximum when looking in the direction of arrows 4 4 in axial tension along a desired line of severance. Fig. 3. f Fracture of the body can then be initiated by Referring to the drawing in detail, the strucabrading it along a portion of this line. If the ture of Figs. 1 and 2 includes a frame Il from the initially applied load is insufficient to create fracupper end of which depends a clevs I2. Frame tue when abrasion occurs, the fracture can be at its lOWel end has a depending link I3 C011.- brought about after abrasion by increasing the .neeted thereto by a piVQtDIl 15- Link I3 et its 103,51, .lower end is pivotally connected by a pin I6 to The mechanical means for carrying out the 011 end Of a leVeI' -T heldin 2. Substantially hOI- present invention may take the form of. one or Zentel plane by apparatus eXtending between more clamping loops composed of wires, ribbons, levelr` I7 and CleViS l2. This apparatus comprises or bands of metal or the like. Such clamping Ve Clamp DVOted t0 CleVS i240?? a Pin I9, and means in introducing peripheral compressive e Clamp 29 PiVOtellY Connected t0 e link zlil forces into the body set up tensional axial stresses turn pivotaily Connected t0 level' |7- Metel Strips in the bore wall surface thereunder and in the 22-25 0f Clock Spring 'materiel OI'ftlle like are laterally adjacent Outer Surfaces the formed into IOOPS Or bands intermediate which may be abradedto initiate `fracture along their ends adapted i0 'receive a glass tube 3|' t0 a desired line of severance be severed. Strips 22--25 at their ends are an- To promote fracture the glass should accord- 4.5 ehei'ed tociemps is and 2li respectively Level' lngly be scored along a line of maximum axial l1 1s provlded With a weight W adjustable theretension Scoring may be Carried out either be on to tighten loops 21-30 about tube 3| -to create fol-e or after placing an article under comprestherein the desired degree of highly localized sive forces. Scoring the article after introduccircumferential COmDIeSSiVe fOICe 0I lead retion of compressive forces, however, is effective quired in the SeVeIIlg Operation- The Vertical at somewhat lower loads than when scoring T1111 0f frame has a plunger 32 Deesing thereprecedes the introduction of such loads. Preferthru, Which Carries an abrasive knife 33 adapted ably, the article is placed underY a vpreliminary to be passed over tube 3| to Score the same by compressive force or load, scored to initiate fracdepressing a button 34.' l .l ture, and then complete fracture produced by in- In the structure of Figs. 3 and 4, a spring clamp Operation In carrying out a severing operaton with the apparatus of Figs. 1 and 2, a tube 3| is passed.

through loops 21-30 with the portion of the tube at which severance is desired located sub-,

stantially midway between loops 28 and 29. For aid in properly positioning, the tube may have a mark 2B which may comprisean ink line, or may actually be the score line for initiating fracture. The weight W is moved toward the free endof lever l1 a distance determined by experiment sufficient to introduce the circumferential compressive force or load needed to create a suitable axial tension in the portion of the tube between loops 28 and 29. If the tube is scored before placement in the loops, the weight is shifted to build up compressive forces thereunder and the necessary accompanying axial tension in the scored area of the tube to complete the fracture. If line 26 is merely an ink mark or the like, the weight may be adjusted to create a fracture as soon as the tube is scored by knife 33. Alternatively, and preferably, the Weight W is first adjusted to place the tube under a compressive load insumcient to cause fracture during scoring, in which case nal severance is effected by increasing the compressive load after scoring.

Severance of tube 3| alongline 2B is carried out in substantially the same way by use of the apparatus of Figs. 3 and 4 as with the apparatus of Figs. l and 2. With the use of the single band 40 arranged in vise 4 I, the area under maximum axial tension on the inner surface of the tube f is located between the lateral margins of the band and accordingly is where the line ofV severance should be located.

It is possible to carry out applicants method by creating the desired compressive force orv load in the tube using a single loop such as 2l or a single pair of loops such as-loops 2l and 28, for example, and scoring the tube along one side thereof. It is also possible to dispense with the use of the second set of loops 21 and 30, using merely loops 2.8 and 29. For best results, however, applicant prefers to employ loops 21-39 or their equivalent, or a single band such as band 4d.

In Fig. Za'the effect of the localized peripheral compressive forces applied by loops 2l to 30 is, for the purpose of illustration, shown greatly exaggerated, and the locations of the resulting circumferential bands of maximum tension are indicated by the letters T. From this view it can at once be seen that when two sets of loops are employed as shown, the most suitable place to effect scoring is on the outer surface ofthe tube midway between the loops, and that when a single pair of loops such as loops 21 and 28 (equivalent to the single band 40 of Figs. 3 and 4) is employed, the most suitable place to effect scoring is on the inner surface ofv the tube at a point midway between the lateral confines of the loops.

As has been stated, the desired line of severance should always coincide as nearly as possible with the location along the tubing at which the circumferential band of maximum axial tension is introduced by the compressive equipment irrespective of whether such equipment comprises a single loop or band or a number thereof. This location depends on several factors, such as wall thickness, tube or cylinder diameter, and the distance from the end of the tube or cylinder at which compressive forces are being applied. Also the character of compressive apparatus employed, such as single or multiple loops or bands and their cross-sectional shapes and/or dimension, may affect the location of the area of maximum tension.

As will be understood, the apparatus disclosed for carrying out applicants methods are for illustrative purposes only, and may be modified or changed within the scope of the appended claims without departing from the spirit or sacricing any of the advantages of the invention.

What is claimed is:

l. The method of severing a hollow frangible vitreous body of circular cross section, which consists of applying circumferentially around the body adjacent the desired line of severance a uniform compressive force of sufficient magnitude to produce a peripheral band of axial tension with the maximum axial tension around such body substantially on the desired line of severance and scoring the body along only a portion of such line. Y

2. A method such as defined by claim l wherein the scoring step precedes placing the body under the compressive load.

3. A method such as defined by claim 1 wherein the step of placing the body under the compressive load precedes the scoring step. i

4. A method such as defined by claim 3, which includes the step of increasing the compressive load after the scoring step.

5. The method of severing a tubular frangible vitreous body of circular cross section, which consists of applying circumferentially around the body adjacent opposite sides of the desired line of severance a uniform compressive force of sufficient magnitude to produce a peripheral band of axial tension with the maximum axial tension around such body substantially on the desired line of severance and scoring the body along only a portion of such line.

6. The method of severing a frangible vitreous tubular body of circular cross section transverse its length, which consists of applying circumferentially around the body adjacent the desired line of severance a uniform compressive force of sufficient magnitude to produce a peripheral band of axial tension with the maximum axial tension around such body substantially along the desired line of severance and scoring the body along only a portion of such line.

7. A severing apparatus consisting of means for scoring a hollow frangible vitreous body of circular cross section along only part of a desired line of severance,` and means for applying circumferentially around the body adjacent the desired line of severance a uniformcompressve force of suicient magnitude to produce aperipheral band of axial tension around the body with the maximum axial tension substantially on the desired line of severance.

8. A structure such as dened by claim' 7 wherein the force applying means includes a linear member looped about the body and means for placing the linear member under tension. y

9. A structure such as defined byV claim 7 wherein the force applying means includes a plurality of linear members formed into loops intermediate their ends for receipt of the body to be 5 6 severed and means for placing said members un- UNITED STATES PATENTS del' tension Number Name Date 999,668 Montaperto Aug. 1, 1911 ROBERT B RMDELS 5 1,892,914 stable Jan. 3, 1933 1 1,922,426 Fahrney Aug. 15, 1933 REFERENCES CITED 2,157,067 Brown et a1. May-2, 1939 The following references are of record in the 2,174,183 Shaw Sept. 26, 1939 le of this patent: 2,219,698 Owen Oct. 29, 1940 

